An Experimental Investigation of Nanoparticles Assisted Surfactant Flooding for Improving Oil Recovery in a Micromodel System

The mechanisms involved in nanoparticle application in enhanced oil recovery processes particularly when nanoparticles are used in conjunction with other chemical agents are still controversial. In this study, the main focus is on pore scale investigation of nanoparticle-surfactant mixture flooding as an enhanced oil recovery process. Five spot glass micro model experiments were conducted to study the oil recovery mechanisms in the presence of hydrophilic silica nanoparticles at various concentrations. Macroscopic oil recovery as well as pore fluid distributions were evaluated by the continuous images taken from the micro model during the injection process. The results represent that wettability alteration is the most important factor contributing to additional oil recovery when nanoparticles exist in the injected solution. Nanoparticles could significantly improve the oil recovery obtained during water and surfactant flooding. The oil film on the pore walls were slightly thinned by the sole surfactant solution while with the addition of nanoparticles, it was completely removed and became strongly water wet surface.